The Security Blanket, January/February 2003, Issue 13

Newsletter for Information Technology Department

The Security Blanket, March/April 2003, Issue 14

Newsletter for Information Technology Department

The Security Blanket, November/December 2002, Issue 12

Newsletter for Information Technology Department

A-1A Supplemental Security Income Program, February 2005

Supplemental security income program

A-1A Supplemental Security Income Program, December 2004

SUPPLEMENTAL SECURITY INCOME PROGRAM

A-1A Supplemental Security Income Program, January 2005

A-1A Supplemental Security Income Program, January 2005

A-1A Supplemental Security Income Program, March 2005

A-1A SUPPLEMENTAL SECURITY INCOME PROGRAM

Renal sodium handling in acute and chronic salt loading/depletion protocols: the confounding influence of acute water loading.

OBJECTIVES: Renal tubular sodium handling was measured in healthy subjects submitted to acute and chronic salt-repletion/salt-depletion protocols. The goal was to compare the changes in proximal and distal sodium handling induced by the two procedures using the lithium clearance technique. METHODS: In nine subjects, acute salt loading was obtained with a 2 h infusion of isotonic saline, and salt depletion was induced with a low-salt diet and furosemide. In the chronic protocol, 15 subjects randomly received a low-, a regular- and a high-sodium diet for 1 week. In both protocols, renal and systemic haemodynamics and urinary electrolyte excretion were measured after an acute water load. In the chronic study, sodium handling was also determined, based on 12 h day- and night-time urine collections. RESULTS: The acute and chronic protocols induced comparable changes in sodium excretion, renal haemodynamics and hormonal responses. Yet, the relative contribution of the proximal and distal nephrons to sodium excretion in response to salt loading and depletion differed in the two protocols. Acutely, subjects appeared to regulate sodium balance mainly by the distal nephron, with little contribution of the proximal tubule. In contrast, in the chronic protocol, changes in sodium reabsorption could be measured both in the proximal and distal nephrons. Acute water loading was an important confounding factor which increased sodium excretion by reducing proximal sodium reabsorption. This interference of water was particularly marked in salt-depleted subjects. CONCLUSION: Acute and chronic salt loading/salt depletion protocols investigate different renal mechanisms of control of sodium balance. The endogenous lithium clearance technique is a reliable method to assess proximal sodium reabsorption in humans. However, to investigate sodium handling in diseases such as hypertension, lithium should be measured preferably on 24 h or overnight urine collections to avoid the confounding influence of water.

A-1A Supplemental Security Income Program, April 2005

SUPPLEMENTAL SECURITY INCOME PROGRAM

A-1A Supplemental Security Income Program, July 2005

A-1A Supplemental Security Income Program, July 2005

On the computational security of a distributed key distribution scheme

In a distributed key distribution scheme, a set of servers helps a set of users in a group to securely obtain a common key. Security means that an adversary who corrupts some servers and some users has no information about the key of a noncorrupted group. In this work, we formalize the security analysis of one such scheme which was not considered in the original proposal. We prove the scheme is secure in the random oracle model, assuming that the Decisional Diffie-Hellman (DDH) problem is hard to solve. We also detail a possible modification of that scheme and the one in which allows us to prove the security of the schemes without assuming that a specific hash function behaves as a random oracle. As usual, this improvement in the security of the schemes is at the cost of an efficiency loss.

A-1A Supplemental Security Income Program, August 2005

SUPPLEMENTAL SECURITY INCOME PROGRAM, August 2005

A-1A Supplemental Security Income Program, September 2005

Supplemental Security Income Program

A-1A Supplemental Security Income Program, October 2005

A-1A - Supplemental Security Income Program - October 2005

A-1A Supplemental Security Income Program, November 2005

A-A1 - Supplemental Security Income Program - November 2005